Terahertz astronomy has been exceptionally unexplored until the last decades due to a technological gap, but exactly at these wavelengths the most distant galaxies appear very bright. Efficient instruments that are capable of spectrometry are essential in understanding the physics of these distant objects. Within the framework of this thesis, an efficient, moderate spectral resolution, on-chip filterbank spectrometer is presented. Several band-pass filter units were investigated and compared, being the directional band-pass filter the most robust and performing. A circuit model is constructed for each of these units and arrayed into a filterbank configuration resorting to microwave techniques. The performance of the filterbank with the circuit model, both with and without realistic losses and tolerances is modeled. A microstrip directional band-pass filter unit has been designed and arrayed into a filterbank chip design. A test filterbank chip based on this design has been fabricated. Due to fabrication issues the detector yield was too poor to allow in-depth and statistically significant measurements. Despite this, the filterbank design is expected to outperform state-of-the-art superconducting filterbanks in terms of coupling efficiency.

This thesis describes the design and prototyping results of a low power wireless power transfer (WPT) system. In particular the design and testing of a transmitter.

Firstly, existing research is discussed and it is found that a significant part of this discusses higher power transfer systems. Here lies the challenge for this thesis: to find an efficient way of transferring a low amount of power wirelessly, with a significant distance between the transmitter and the receiver. Also, existing WPT standards were investigated and their shortcomings are discussed.

Secondly, the design of the transmitter is discussed. It starts out with the fundamental and circuit theory behind wireless power transfer. With this, it is found that tuning capacitors can greatly increase the efficiency of the system. Next, the design of the components in the coupled coils system is discussed, with calculations on equivalent series resistance for different frequencies. Furthermore, the functional block diagram consists of an oscillator, gate driver and inverter circuit and its design choices are discussed. The design concludes with a frequency optimization and simulation results.

Lastly, the design has been built and tested. A transmitter efficiency of 93.4 % has been reached at a coupling of around 0.1. This is at a distance of 20 millimeters. Further improvements may be done with the gate-driver. Control techniques may also prove beneficial for future work.